O’Rourke kicked off his campaign March 31 with a rally in his hometown of El Paso, which he represents in Congress, followed by a weekend of stops in major cities around the Lone Star State.

Without mentioning Cruz by name, O’Rourke accused him of putting political ambition above his job as a senator, saying that to meet the challenges of the future, Texans will need “a senator who’s working full time for Texas, a senator who’s not using this position of responsibility and power to serve his own interests, to run for president, to shut down the government.”

O’Rourke kicks off campaign in El Paso.

O’Rourke is also positioning himself as principled opponent to President Donald Trump, saying the new administration is “focused on the wrong things instead of the right things that (are) going to get us ahead,” such as a ban on refugees from Muslim counties, an immigration crackdown and construction of wall along the U.S.-Mexico border.

“We can decide that we’re going to take back this country, and we’re going to take back this state, and that we’re going to do that in 2018,” he said. “2018 starts right here, right now.”

O’Rourke, who had previously made a commitment to serve no more than four terms in the House, said that if elected, he would serve only two six-year terms in the Senate. He took a shot at the Washington political class, saying the American people need a Congress “that actually works, that’s not more preoccupied and focused on the re-election of its members than the business of this country.”

O’Rourke, 44, was first elected to the House in 2012, representing the majority Latino 16th District, which takes in most of El Paso County and borders Mexico. He has strong political roots in El Paso, where his father, Pat, served as county judge.

Although the first name he uses, Beto, is a common Spanish nickname for his given name, Robert, O’Rourke is Irish, not Latino. He acquired the nickname in childhood.

O’Rourke will face an uphill battle against Cruz, given that no Democrat has won a statewide office in Texas since 1994 or a Senate race since 1988. His background and liberal policy positions may also prove to be a difficult sell.

O’Rourke played in a rock band in the early 1990s and was later arrested, but not convicted, on burglary and drunk driving charges. He is a supporter of LGBT rights and an opponent of what he calls the “failed war on drugs.” He supports comprehensive immigration reform and participated in a 2016 sit-in by House members in support of stronger restrictions on gun purchases.